Assembly to wind cords in a motorized window covering

ABSTRACT

An assembly for winding cords in a motorized window covering with a headrail having a length suitable for extending between opposite sides of an architectural opening, a winding reel that is substantially in the shape of a tube, a motor that fits substantially within the winding reel, a driver that is rotationally coupled to the output shaft of the motor that allows the winding reel to slide axially with respect to the driver, a threaded adapter that has a threaded segment that is substantially fixed to the winding reel, a threaded fitting that has threads that mesh with the threaded adapter such that the winding reel travels axially as it spins, and a crown that allows the winding reel to slide axially with respect to the crown throughout the winding reel&#39;s limits of travel.

CROSS REFERENCE TO RELATED APPLICATIONS

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

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REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX

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BACKGROUND OF THE INVENTION

This invention relates to a new assembly to wind the cords in a motorized window covering, such as a blind, shade, curtain, drapery, etc. The key objective of this invention is to wind the cords without overlapping, bunching up, or tangling. In window coverings it is normally preferred to wind cords in an even, regular manner in order for the blind to operate consistently and for the bottom-rail, or end-slat, to remain level as it rises, or moves. Conventional methods of winding cords are fraught with problems: tangling, bunching up, overlapping, etc. There are known methods for dealing with these problems. But there isn't any known thread-related reel mechanism that prevents bunching in a manner taught by this invention. A list of closely related, but different, patents are listed below.

U.S. Patent Numbers Issue Date Inventor 1,808,455 June, 1931 Duncanson 1,978,152 October, 1934 Ward 3,310,099 March, 1967 Hunter, et. al. 3,603,372 September, 1971 Dietzsch 4,623,012 November, 1986 Rude, et. al. 4,726,410 February, 1988 Fresh 5,150,846 September, 1992 Giust et. al. 5,328,113 July, 1994 Villette, et. al. 6,158,494 December, 2000 Huang 6,230,784 May, 2001 Sanz 6,736,184 May, 2004 Eaton

BRIEF SUMMARY OF THE INVENTION

The invention relates to an innovative assembly to wind cords in a motorized window covering. This invention has a variety of aims:

-   -   winds cords evenly and consistently without overlap, tangling,         or bunching up does not require a cone reel system, tape lift         cords, or a floating reel system requires minimum route space     -   applicable to many different types of motorized window coverings     -   can be used on many different sizes of architectural openings     -   can be used with tubular motors     -   is functionally reliable         This invention of patent-able novelty and utility accomplishes         these and many other objectives.

In one embodiment, the invention uses a winding reel that is substantially in the shape of a tube. A motor is substantially enclosed within the winding reel. To couple to rotational motion of the motor's output shaft to the winding reel a driver is used. The driver is coupled to the output shaft of the motor in a manner that causes the winding reel to rotate synchronously with the motor's output shaft. The driver also allows the winding reel to slide axially. A threaded adapter is connected to the winding reel, and a separate threaded fitting is used. The threads on the threaded adapter are mated to the threads on the threaded fitting, and the threaded fitting is affixed to an object that is external to the winding reel and motor. This causes the winding reel to travel axially as the motor spins. A crown may be employed to support one end of the winding reel. The crown may also drive limit switches If a crown is used, it would have a length that is sufficient to substantially support the winding reel throughout the winding reel's limits of travel. The result is an assembly that winds cords in a predictable, consistent manner.

A second embodiment of the invention also uses a winding reel that is substantially in the shape of a tube. A motor is substantially enclosed within the winding reel. To couple to rotational motion of the motor's output shaft to the winding reel a driver is used. The driver is rotationally and axially coupled to the output shaft of the motor, which causes the winding reel to move axially and rotationally with the motor's output shaft. A threaded adapter is fixed to the winding reel, and a separate threaded fitting is used. The threaded adapter is mated to the threaded fitting, and the threaded fitting is affixed to an object that is external to the winding reel. As the motor spins the winding reel and motor are both driven axially. The motor is mounted to a mounting bracket that is free to slide to slide axially as the motors output shaft spins. The result is that the motor and winding reel move axially, together, as the winding reel spins, to effectuate consistent winding of the cords. Alternatively the mounting bracket may be fixed in position, and the coupling between the motor mount and motor may be sliding coupled. This alternate configuration performs the same function.

Other embodiments of the invention can be created, but are not described.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a complete blind.

FIG. 2 is an overhead view of the headrail 1 of a blind.

FIG. 3 is an overhead view of the headrail 1 of a blind. This drawing has the motor removed, and does not include the winding reel 28. This figure shows additional details that may have been covered by the winding reel 28 and motor 19.

FIG. 4 is view of a complete headrail 1 from an end-view perspective.

FIG. 5 is a side view of the diverter 34.

FIG. 6 is a top view of the diverter 34.

FIG. 7 is a perspective view of the diverter 34.

FIG. 8 is an alternate perspective view of the diverter 34.

FIG. 9 is an illustration that shows how the lift cords 32 33 and tilt cords 41 42 could be routed in a configuration that has one lift cord 33 per lift point.

FIG. 10 is an illustration that shows how the lift cords 32 33 and tilt cords 41 42 could be routed in a configuration that has two lift cords 32 33 per lift point.

Equivalent reference numerals are used to refer to identify similar parts throughout the several views of the drawings.

DESCRIPTION OF PRIOR ART

A variety of methods have been employed to wind cords in a uniform, consistent manner. The common method used today uses a reel that is approximately in the shape of a cone. The cone is constructed from a low-friction material. The cone-shaped reel spins as it adds windings. As it spins the new windings push the existing windings toward the narrow end of the cone-shaped reel to make room for the new windings. As a result, there is always a vacant area on the reel for new windings, and the windings never overlap. Another method of achieving even, consistent windings uses a thin tape, in place of the lift cords. The tape is thin enough that the layers of tape can be wrapped on top of one another. The reel is approximately as wide as the tape. Each new winding lies directly over of the previous winding, such that the winding occurs in a consistent manner. Another method uses a reel that can freely slide axially as it spins. This configuration causes the windings to wrap evenly because each new winding of the cords causes the reel to shift axially as new windings are added. As a result, the cords wind evenly. Another method involves employing a threaded mechanism to drive the reel such that it will move axially as the reel spins. This invention employs a threaded mechanism in a new and innovative manner that is not present in the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment describes a venetian blind. However the invention is applicable to any type of covering for an architectural opening, that employs a plurality of parallel slats 2 including venetian blinds, vertical blinds, cloth blinds such as those that suspend fabric slats between two sheer fabric facings, and other types of coverings with a slats 2.

Many different embodiments are possible. An image of the preferred embodiment is shown in FIG. 1. The preferred embodiment is one particular venetian blind, however, practical application other embodiments of venetian blinds, and to other types of blinds, can be carried out by those skilled in the art.

FIG. 2 shows a close-up view of the headrail 1 and the other components that are installed in the headrail 1. This embodiment utilizes a single tubular motor 19 to serve the purpose of driving both the lift and tilt functions of the blind. The motor 19 is substantially contained within the headrail 1. The type of motor 19 selected for the preferred embodiment is commonly referred to as a tubular motor 19. These motors are commonly used today in various window coverings, awnings, projection screens, etc. The tubular motor 19 used in this embodiment is bi-directional and includes a self-contained gearbox, brake, and limit switches. Components on the motor 19 include a mounting shaft 81, a crown 35 which drives the limit switches, limit switch set screws 15 16, and an output shaft 21, as shown in FIG. 3. The motor 19 also has a four-sided, square, mounting shaft 81. In this embodiment this mounting shaft 81 is inserted into a complementary hole in the motor mount 11. Then a pin is placed through the hole in the mounting shaft 81 to keep the mounting shaft 81 from sliding out of the motor mount 11.

The motor 19 is mounted rigidly to the headrail 1 at one end, via a motor mount 11. A winding reel 28 is placed around the motor 19 and a driver 34 connects the output shaft 21 of the motor to the winding reel 28 so that the power of the motor 19 causes the winding reel 28 to rotate around the motor 19. The winding reel 28 is a substantially in the shape of a tube. FIG. 3 is a closer up view the same headrail 1 without the winding reel 28 to reveal the components inside. FIG. 3 also has the motor 19 removed to reveal the components inside the headrail 1. FIG. 4 is an end-view of the same headrail 1 of FIG. 2.

The headrail 1 itself in this embodiment is made from extruded aluminum. The headrail 1 has symmetrical ridges 47 48 near the bottom of the headrail 1 profile that are an integrated part of the extrusion profile. These ridges 47 48 serve the function of holding the motor mount 11 and threaded fitting mount 24 in place. The motor mount 11 and threaded fitting mount 24 both have a tab that snaps into a hole in the headrail 1. This tab prevents the motor mount 11 and threaded fitting mount 24 from sliding within the channel. Other methods of mounting the motor mount 1 and threaded fitting mount 24 are possible. These methods may include, but are not limited to screws, rivets, adhesives, brazing soldering, welding, pressure fittings, etc.

The motor mount 11 for the motor 19, and the threaded fitting mount 24, are both connected in this manner. However, the threaded fitting mount 24 doesn't attach directly to the motor 19. Instead, the threaded fitting mount 24 has a round, threaded hole in it. A threaded fitting 26 is placed through the hole in the threaded fitting mount 24. In this embodiment a standard, off-the-shelf bolt is used as the threaded fitting 26. A nut 27 and washers 30 40 are used in this embodiment to secure the threaded fitting 26 in place. Onto the threaded fitting 26, a threaded adapter 31 is installed. The threaded adapter 31 in this embodiment has internal threads that match the external threads of the threaded fitting 26. The winding reel 28 and the threaded adapter 31 are fixed to each other.

The threaded fitting 26 and threaded adapter 31 serve the purpose of causing the winding reel 28 to travel axially as the winding reel 28 spins. This axially movement allows the lift cord 33 to wind evenly because a vacant section of the winding reel 28 will be presented to each new length of lift cord 33 that approaches the winding reel 28, as the winding reel 28 spins. The result is that the bottomrail 3 remains level as it rises.

To link the power of the motor 19 to the winding reel 28 a driver 34 is used. The driver 34 couples the output shaft 21 of the motor 19 to the winding reel 28. The output shafts 21 of tubular motors 19 typically have two flat sides that are parallel to each other and two rounded sides that are opposite each other. The driver 34 fits onto the output shaft 21 and is normally held in place with a clip that fits into a groove in the end of the output shaft 21. The driver in this embodiment 34 has physical contours on its exterior surface that fit complementary physical contours on the interior of the winding reel 28. This arrangement rotationally connects the motor 19 to the winding reel 28. No screws, or rivets, or other rigidly connecting devices are used to connect the driver 34 to the winding reel 28. The winding reel 28 is allowed to slide axially over the driver 34.

The second end of the winding reel 28 fits around the crown 35 on the motor 19. The crown 35 on the motor 19 is driven by the winding reel 28. The crown 35 also serves the function of supporting the end of the lift tube 28. The lift tube 28 is allowed to slide axially over the crown 35. Consequently the crown 35 is long enough to support the winding reel 28 throughout the total distance that the winding reel 28 may axially travel. This embodiment uses a crown 35 that is that is integrated into the motor 19. It is normal for the crown 35 to also drive the motor's limit switches.

There are two limit-switch set screws 15 16 on the motor 19. The first set screw 15 determines that maximum clockwise position of the motor 19 and the second set screw 16 determines the maximum counterclockwise position of the motor 19. The rotational limits of the motor 19 can be established by setting the screws 15, 16 to the appropriate position. When the motor 19 reaches a predetermined position, as determined by the set screws 15 16, the motor 19 stops.

The 33 lift cords are attached to the winding reel 28. Many different means of attaching cords 32 33 41 42 are possible. A common method to attach cords 32 33 41 42 to winding reels 28 is to first mount the cords 32 33 41 42 to the winding reel using an adhesive tape that has a chemistry that is compatible with the cords 32 33 41 42. Then a clip is placed over the adhesive tape. The clip fits substantially around the winding reel 28. Finally, the cords 32 33 41 42 are wrapped around the tube a few times, to diminish any pressure on the tape. An alternate method that is used by this embodiment uses a winding reel 28 with ribs that run along its length. A hole is drilled through these ridges at each location that a cord 32 33 41 42 is connected. The cord 32 33 41 42 is fed through the hole. Then the cord 32 33 41 42 is either knotted, or a small metal crimp is pressure-fitted onto the cord 32 33 41 42 so that the end of the cord 32 33 41 42 cannot slip through the hole.

The lift cord 33 runs vertically from the headrail 1 down to the bottom of the blind. The lift cord 33 cattaches to the bottomrail 3 and performs the function of lifting the bottomrail 3. Some venetian blinds are built such that they lift the bottomrail 3 at just two lift points. However, wider blinds may have additional lift points interposed between the lift points that are at end of the blind. The preferred embodiment illustrates a lift cord 33 configuration that employs one lift cord 33 at each lift point. One end of the lift cord 32 is attached to the bottomrail 3. The lift cord 32 is then routed up through a hole in each of the blind slats 2. After being routed through a hole in each of the blind slats 2 the lift cord 33 is routed through a hole in the diverter 8, which brings the cord through the bottom of the headrail 1. The diverter 8 has seven routings holes in it. The routing holes provide a path to that the lift cords 32 33 and tilt cords 41 42 can be routed through the diverter 8, allowing them to pass through the headrail 1. The seven routing holes make it possible for one diverter 8 to accommodate a variety of different slat widths and different routing configurations. The diverter 8 of the preferred embodiment is illustrated in FIG. 5, FIG. 6, FIG. 7, and FIG. 8. Each of the illustrations in FIG. 5, FIG. 6, FIG. 7, and FIG. 8 are the same part, but are shown from different angles. After routing the lift cord 32 through the routing holes 88 in the diverter 8, the lift cord 32 is then connected to the winding reel 28. This routing method is illustrated in FIG. 9.

Another method employs dual-lift-cords at each lift point. The dual-lift-cord method doesn't normally utilize slats 2 with holes through them. Instead the lift cords 32 33, are routed with one lift cord 32 33 on each side of the slats 2. This is commonly referred to as the routeless method. Both lift cords 32 33 wind around the winding reel 28. In the routeless, dual-lift-cord method, care must be taken to prevent the interference and overlapping of the two lift cords 32 33. FIG. 10 illustrates how this configuration might be routed. Consistent, even winding of dual cords 32 33 from the same lift point is achieved by diverting one of the lift cords 32 33. This method causes the lift cords 32 33 to wind around the winding reel 28 at different points along the axis of the winding reel 28. A diverter 8 has a diverting loop 9 that is used to redirect one of the lift cords to a different section of the winding reel 28. Each of the lift cords 32 33 are also attached to the winding reel at different points relative to axis of the winding reel 32 33. Many other lift cord embodiments may also be employed to consistently wind dual lift cords 32 33.

The preferred embodiment is a venetian blind application, so the details described apply specifically to venetian blinds. Venetian blinds typically have two or more ladderbraids to effectuate the tilting function. Ladderbraid consists of two tilt cords 41, 42 and a plurality of cross-members that connect the two tilt cords 41, 42. Each slat 2 of the blind rests on a separate cross-member of the ladderbraid.

Tilt cords 41 42 are responsible for controlling the angle of the slats 2. The tilting is normally accomplished by effectively lifting one of the tilt cords 41 42 higher, or further, than the other tilt cord 41 42. Many blinds have just two ladderbraids—one at each end of the blind. However, wider windows often have additional ladderbraids interposed between the ladderbraids at each end. Each of the ladderbraids normally runs vertically from the headrail 1 down to the bottomrail 3 of the blind. Those skilled in the art can determine how many ladderbraids are needed for a particular application.

Slats 2 are a group of parallel members that allow light to pass when the slats 2 are angled in a particular direction, but which substantially block light when the angle of the slats 2 has changed. These parallel members may be called slats, vanes, ribbons, strips, planks, blades, or other names. However, here they are referred to simply as slats 2. Throughout the description, the function of changing the physical location, or position, of the slats 2 is referred to as lift, or lifting. The function of changing the angle of the slats 2 is referred to as tilt, or tilting.

Ladderbraid is described in the preferred embodiment because ladderbraid is commonly used in venetian blinds. However, many other types of cords, or linkages may be employed to control the angle of the slats 2. For example in a vertical blind the slats 2 are commonly hung from rotating member. The angle of the rotating member is commonly driven with cords or chain-type linkages. In cloth blinds such as those that suspend fabric slats between two sheer fabric facings, the sheer fabric facings perform the same function as the ladderbraid and tilt cords. Other types of blinds use other types of mechanical linkages to connect each of the individual slats. In each case the tilting is controlled by controlling the position of two relative position of each edge of the slats. Likewise, it is possible to control the angle of slats 2 by controlling just one slat edge. However, for aesthetic reasons the common practice is to control both slat edges simultaneously.

Tilt cords are discussed throughout the preferred embodiment. Tilt cord could be any of many types of connecting devices. This could include, but is not limited to belts, chains, straps, tapes, webbing, direct linkages, rods, connector pieces, cloth sheets, wires, etc. The tilt cords could be solid pieces, or flexible pieces, or a combination of the two. Many embodiments are possible.

In the preferred embodiment the end of the first tilt cord 41 42 is attached to a first side of the bottomrail 3. The second tilt cord 41 42 is attached to the second side of the bottomrail 3. The tilt cords extend vertically up from the bottomrail 3. A plurality of parallel cross-members connect the two tilt cords 41 42. Normally one slat is placed upon each cross-member of the ladderbraid. Sometimes the ladderbraid has an additional cross-member that runs across the top of each slat 2, in addition to the cross-member that is below each slat 2.

There are two tilt cords 41 42. To mechanically connect the tilt cords 41 42 to the motor 19, a first tilt cord 41 is routed up through the bottom of the headrail 1, then the first tilt cord 41 is routed around the top of the winding reel 28, then back down through a hole in the headrail 1. The tilt cord 41 rests on the winding reel 28. After exiting the headrail 1, the first tilt cord 41 is then connected to the second tilt cord 42. For aesthetic and functional reasons the two tilt cords 41 42 are normally connected at a point just below the slat 2 that is nearest to the headrail 1. They can be connected with a small metal band that can be crimped to hold the two lift cords 41 42 together.

For illustrative purposes just one pair of tilt cords 41 42 are displayed in FIG. 2. However, there may be additional sets of tilt cords 41 42 needed to control the blind. Those skilled in the art can determine how many tilt cords 41 42 are necessary for a particular application.

A second embodiment maintains many similarities to the preferred embodiment that has been previously described. However, in the second embodiment the winding reel 28 and the motor 19 are coupled so that they travel axially together. In this embodiment, the driver 34 and winding reel 28 are connected with a screw, or rivet. Likewise, the driver 34 is also coupled to the motor 19. As the winding reel 28 spins it causes the threaded adapter 31 to simultaneously spin. The threaded adapter 31 is mated to the non-moving threaded fitting 26 which causes the winding reel 28 to travel axially as the threaded adapter 31 spins. The motor mount 11 is slidingly connected to the headrail 1. The resulting configuration causes the winding reel 28 to travel axially as it spins and allows the lift cords 32 33 to wind evenly.

Alternatively the motor mount 11 may be fixed to the headrail 1, and the motor mount 11 and motor 2 may be sliding coupled. This alternate configuration of the second embodiment allows the winding reel 28 to travel axially as it spins, and perform the same function. Only two embodiments are discussed, although many other embodiments are possible. 

1. An assembly for winding cords in a motorized window covering comprising: a headrail, said headrail having a length suitable for extending between opposite sides of an architectural opening; a winding reel, said winding reel that is substantially in the shape of a tube; a motor, said motor that has an output shaft, said motor that fits substantially within said winding reel; a driver, said driver that is rotationally coupled to said output shaft, said driver that is rotationally coupled to said winding reel, said driver that allows said winding reel to slide axially with respect to said driver; a threaded adapter, said threaded adapter that has a threaded segment, said threaded adapter that is substantially fixed to said winding reel; a threaded fitting, said threaded fitting that is substantially fixed in placed that has threads that mesh with said threaded adapter such that said winding reel travels axially as it spins; a crown; said crown that allows said winding reel to slide axially with respect to said crown throughout said winding reel's limits of travel.
 2. The assembly of claim 1 wherein one or a plurality of cords are attached to said winding reel.
 3. The assembly of claim 1 wherein one or a plurality of cords slidingly contact said winding reel.
 4. The assembly of claim 1 wherein said threaded adapter has internal threads and said threaded fitting has external threads.
 5. The assembly of claim 1 wherein said threaded adapter has external threads and said threaded fitting has internal threads.
 6. The assembly of claim 1 wherein one or a plurality of diverters guide one or a plurality of cords along predetermined paths.
 7. An assembly for winding cords in a motorized window covering comprising: a headrail, said headrail having a length suitable for extending between opposite sides of an architectural opening; a winding reel, said winding reel that is substantially in the shape of a tube; a motor, said motor that has an output shaft, said motor that fits substantially within said winding reel; a driver, said driver that is substantially fixed to said output shaft; a threaded adapter, said threaded adapter that is substantially fixed to said winding reel; a threaded fitting, said threaded fitting that has threads that mesh with said threaded adapter such that said winding reel travels axially as it spins; a motor mount; said motor mount that is slidingly attached to said motor, said motor mount that is fixed to said headrail.
 8. The assembly of claim 7 wherein one or a plurality of cords are attached to said winding reel.
 9. The assembly of claim 7 wherein one or a plurality of cords slidingly contact said winding reel.
 10. The assembly of claim 7 wherein said threaded adapter has internal threads and said threaded fitting has external threads.
 11. The assembly of claim 7 wherein said threaded adapter has external threads and said threaded fitting has internal threads.
 12. The assembly of claim 7 wherein one or a plurality of diverters guide one or a plurality of cords along predetermined paths.
 13. An assembly for winding cords in a motorized window covering comprising: a headrail, said headrail having a length suitable for extending between opposite sides of an architectural opening; a winding reel, said winding reel that is substantially in the shape of a tube; a motor, said motor that has an output shaft, said motor that fits substantially within said winding reel; a driver, said driver that is substantially fixed to said output shaft; a threaded adapter, said threaded adapter that is substantially fixed to said winding reel; a threaded fitting, said threaded fitting that has threads that mesh with said threaded adapter such that said winding reel travels axially as it spins; a motor mount; said motor mount that is attached to said motor, said motor mount that is slidingly attached to said headrail.
 14. The assembly of claim 13 wherein one or a plurality of cords are attached to said winding reel.
 15. The assembly of claim 13 wherein one or a plurality of cords slidingly contact said winding reel.
 16. The assembly of claim 13 wherein said threaded adapter has internal threads and said threaded fitting has external threads.
 17. The assembly of claim 13 wherein said threaded adapter has external threads and said threaded fitting has internal threads.
 18. The assembly of claim 13 wherein one or a plurality of diverters guide one or a plurality of cords along predetermined paths. 